This specification relates to data processing.
The Internet provides access to a wide variety of resources. For example, video and/or audio files, as well as web pages for particular subjects or particular news articles are accessible over the Internet. Access to these resources presents opportunities for advertisements to be provided with the resources. For example, a web page can include advertisement slots in which advertisements can be presented. These advertisements slots can be defined in the web page or defined for presentation with a web page, for example, in a pop-up window.
When a web page (or another resource) is requested by a user, an advertisement request is generated and transmitted to an advertisement management system that selects advertisements for presentation in the advertisement slots. The advertisement management system selects advertisements, for example, based on characteristics of the web page with which the advertisements will be presented, demographic information about the user to whom the advertisements will be presented, and/or other information about the environment in which the advertisement will be presented.
Advertisements that are presented in the advertisement slots can include a portion of code that, in response to user interaction with the advertisement, causes a user device to request presentation of a specified resource (e.g., a web page for the advertiser). In order to track the user interactions with the advertisement, the request for the specified resource may be redirected through one or more servers (“intermediary servers”) prior to being received by a server that provides the specified resource in response to the request (“destination server”). Each redirect that is performed increases the time from when the user takes action to access the specified resource until the specified resource is received by the user device, and increases the likelihood of an error occurring that prevents the specified resource from being provided to the user device.